Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.

Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.


Calcium may harm heart

25 May 2012, 10:42

 Calcium supplements might increase the risk of having a heart attack, and should be "taken with caution," concludes research published in the online issue of the journal Heart.

Furthermore, boosting overall calcium intake from dietary sources confers no significant advantage in terms of staving off heart disease and stroke, the findings indicate.

Previous research has linked higher calcium intake with a lowered risk of high blood pressure, obesity, and type 2 diabetes, all of which are risk factors for heart disease and stroke. And calcium supplements are commonly recommended to elderly people and women who have gone through the menopause to prevent bone thinning.

How the study was done

The authors base their findings on almost 24 000 participants of one of the German arms of the European Prospective Investigation into Cancer and Nutrition (EPIC) study in Heidelberg.

All the participants were aged between 35 and 64 when they joined the study in 1994-8. Normal diet for the preceding 12 months was assessed using food frequency questionnaires and they were quizzed about whether they regularly took vitamin or mineral supplements.

Their health was tracked for an average of 11 years, during which time 354 heart attacks, 260 strokes, and 267 associated deaths occurred.

Calcium intake ups risk of stroke?

After taking account of factors likely to influence the results, those whose diets included a moderate amount (820 mg daily) of calcium from all sources, including supplements, had a 31% lower risk of having a heart attack than those in the bottom 25% of calcium intake.

But those with an intake of more than 1100 mg daily did not have a significantly lower risk. There was no evidence that any level of calcium intake either protected against or increased the risk of stroke, which backs up the findings of other research, say the authors.

But when the analysis looked at vitamin/mineral supplements, it found that those who took calcium supplements regularly were 86% more likely to have a heart attack than those who didn't use any supplements.

And this risk increased further among those who used only calcium supplements. They were more than twice as likely to have a heart attack as those who didn't take any supplements.

The authors conclude: "This study suggests that increasing calcium intake from diet might not confer significant cardiovascular benefits, while calcium supplements, which might raise [heart attack] risk, should be taken with caution."

In an accompanying editorial, Professors Ian Reid and Mark Bolland from the Faculty of Medical and Health Science at the University of Auckland in New Zealand, say that the safety of calcium supplements "is now coming under increasing scrutiny."

Dietary calcium is helpful

They point to previous research, showing a link between these supplements and kidney stones, and gut and abdominal symptoms, and note that while trial evidence suggests that calcium supplements cut levels of cardiovascular risk factors, this doesn't actually translate into fewer heart attacks and strokes.

They also suggest that many women taking calcium supplements to ward off brittle bones are already healthier than those who don't, and that the overall protective effect is modest—in the order of just 10%.

The evidence that dietary calcium is helpful while calcium supplements are not can be explained by the fact that dietary calcium is taken in small amounts, spread throughout the day, so is absorbed slowly, they say.

Supplements, on the other hand, cause calcium levels in the blood to soar above the normal range, and it is this flooding effect which might ultimately be harmful, they suggest.

"Calcium supplements have been widely embraced by doctors and the public, on the grounds that they are a natural and therefore safe way of preventing osteoporotic fractures," they write.

"It is now becoming clear that taking this micronutrient in one or two daily [doses] is not natural, in that it does not reproduce the same metabolic effects as calcium in food," they say. Given that it is neither safe nor effective, boosting calcium intake from supplements should be discouraged, they contend.

And they conclude: "We should return to seeing calcium as an important component of a balanced diet, and not as a low cost panacea to the universal problem of postmenopausal bone loss."

- EurekAlert


Read News24’s Comments Policy

Comment on this story
Comments have been closed for this article.

Read more from our Users

Nigeria @ 56: Words to my green f...

A leader’s job is not to dictate, but rather to be respected, admired and be a trustee, of the land we love, with so much potential, a land which should be freer than free. Its still a long way to fufilling our destiny! Read more...

Submitted by
Isaac Asabor263
Recession: An opportunity for Nig...

The recession should be seen as an opportunity for the country’s promotion as long as we all collectively conduct ourselves in a patriotic manner, writes Isaac Asabor.  Read more...

Submitted by
Black and White

We want to imitate the whites in everything because we are ignorant of our inherent originality and content. We spend all our Naira to acquire his inventions because we so oblivious of our natural endowments that we allow him have it for free. Read more...

Submitted by
Nate Nat
Adamawa State University Mubi: A ...

ADSU integrity forum has accused the Sunday Joshua Wugira, a lawyer, of adopting unorthodox tactics by abusing his privilege by attacking the integrity of ADSU Vice Chancellor Dr. Moses Zira Zaruwa, writes a News24 reader. Read more...

Submitted by
Abdulsalam Jubril
My Country Nigeria (Part One)

Poetry by Abdulsalam Jubril.

Submitted by
Abdulsalam Jubril
Recession, dearth in leadership a...

Every leader has the opportunity to become great and making himself immortal in the lives and hearts of people for generations to come. Will Mr. President seize this opportunity?, questions Abdulsalam Jubril. Read more...